Hot top water heater



Nov. 17,1931.

J. STONE 1,832,332

HOT TOP WATER HEATER Filed May 21. 1928 i t r i a x m R N gvwemto'aJAMES L. STONE.

351 115 flbi ogfaml Q Patented Nov. 17, 1931 UNITED STATES PATENT OFFICEJAMES L. STONE, 0F SPOKANE, WASHINGTON, ASSIGNOR '10 DOHERTY RESEARCHCOMPANY, OF NEW YORK, N. Y., A CORPORATION 01! DELAWARE nor 1'01? warns.mm

Application filed Kay 21, 1928. Serial No. 279,388.

The present invention relates to gas-fired domestic water heaters. Awater heater capable of satisfactory'and profitable operation on a lowfiat or fixed rate, regardless of the gas consumed, has been desired forsome time by thejmanagers of gas plants, in order to meet competitionfrom electric and coal fired heaters.

Gas fired flat rate water heaters, however, are at present used in onlya limited number of places. The problem of providing an apparatus ofthis character satisfactory in more than a limited area has proved adiflicult one. The apparatus must be cheap to manufacture and adaptedfor use in either 'old or newly installed stand boilers under a widevariety of conditions." Also, the burner must operate at low rates ofgas flow while maintaining a high rate of thermal efficiency or amountof water heated per unit of gas consumed. This is for the reason that ahigh gas flow, even for a short time, requires a correspondingly highinvestment in gas-making apparatus. It is desirable, moreover, that theapparatus shall cause a minimum difficulty when used to heat hard water.It should also be simple, durable and not easily put out of order.

It is one object of the present invention to provide a as-fired waterheater which shall meet the a oVe-mentioned requirements.

Another object of the resent invention is to provide an improvearrangement for catching the condensation-dri from the tubes of a flatrate domestic water eater.

Further objects and advantages of the apparatus according to the presentinvention will be apparent to those skilled in the art from thefollowing description taken in connection with the accompanying drawingin 4a which:

section for purposes of illustration.

Referring to the drawing more in detail, 10 indicates the ordinarydomestic stand boiler, or hot water boiler, 12 indicates the usualconnection to the cold water supply and 14 the pipe connecting the standboiler 10 to the piping of the house. Pipe 16 connects the lower portionof the boiler 10 with the lower portion of water chamber 18. Water to beheated is taken from the lower portion of stand boiler 10 by means ofpipe 16, heated in the water chamber 18 and returned to the pipe 14 bymeans of ipe 20. If a. faucet is opened, of course, the ot water runsdirectly toward the faucet after entering pipe 14, otherwise it turnsinto the tank 10 where it is stored. In the apparatus illustrated in thedrawing the water chamber 18 is formed of two lengths 22, 22 of largepipe forming parallel legs and having a ca 24 at the top and a cap 26 atthe bottom. T e cap 24 forms a water connection at the top between thepipe lengths 22.

The pipe 20 for taking hot water from the chamber 18 is connectedthrough the top of the cap 24. The lower cap 26 closes the chamber 18 atthe lower ends of both the pipe lengths 22. Ca 26 has two aperturesthrough which exten two fire-tubes 28, 28. The tubes 28 are smaller thanthe pipes 22 and extend upwardly through the center of the tubes 22.Preferably tubes 28 are about one inch smaller in diameter than tubes 22so that only a relatively small amount of water is held in the chamber18 and this amount can be quickly heated even by a as fiame using asmall amount of gas. Tu

28 project beyond the upper ends of the tubes. 22 into the cap 24 andthe upper ends of tubes 28 are connected within the cap 24 by a len h 30of tubing, parts 28, 28 and 30 being wel ed together as illustrated andthereby forming an inner fire-tube of inverted U-shape within theheating chamber 18. J

Tubes 28 0 en at their lower ends to receive and disc arge hot gases forheating the water in chamber 18. In the arrangementillustrated, a gasburner 32 is arranged to discharge upwardly into the lower end of one ofthe tubes 28. In the majority of household installations the burner 32is set to consume approximately five cubic feet of gas per hour. Gas forburner 32 is controlled preferably by a thermostat valve 33, so that thegas to burner 32 is reduced whenever the hot water line in tank 10 hasadvanced downwardly to near the bottom of the tank. The hot products ofcombustion from burner 32 pass upwardly through one tube 28 across tube30 and down through the other tube 28.

Suitable arrangements are provided which will be described more indetail hereinbelow for conducting oil the gases which have passedthrough the fire tubes 28 and 80. It has been found that sufiicientcondensation occurs within the tubes 28 to require some provision forcarrying it away. It is preferred, according to the present invention,to combine the means for handling the condensation with the means forcarrying of? the gases of combustion. In the arrangement illustrated,the means for the purposes just mentioned include a box or chamber 34the top of which is formed by the bottom cap of the box 26'and the sidewalls of which enclose the lower ends of the fire-tubes 28. The gas pipefor the burner 32 passes through one side wall of the chamber 34 and theprodnets of combustion discharged from one of the tubes 28 pass out fromthe chamber 34 through its opposite side wall at the point 36 at whichpoint a connection may be made to the flue or chimney. In order toprevent hot gases of combustion discharged from one of the pipes 28 frompassing across through the box 34 and entering the other pipe 28 topartially smother "he fiame or" the burner 32 a partition 38 is placedin chamber 34 intermediate the lower ends of the tubes 28 and extendingfrom the lower surface of the cap 26 downwardly to near the bottom ofthe chamber 3 1. The two parts of chamber 84 on opposite sides ofpartition 38 are, however, connected by a passage 39 through the loweredge of the partition 38. Condensate from the tubes 28 may therefore bedrained out of the bottom of the chamber 34 as fast as it is formedthrough a single pipe 42 leading downwardly through the bottom ofchamber 34, but without danger of mixing any of the products ofcombustion with the air for burner 32. The caps 24 and 26 are preferablyof boiler tubing hammered to lit the ends of pipes 22.

Chamber 18 is covered by heat insulating lagging 40 and tank 10 iscovered by heat insulating lagging 42.

It will be understood that in. the operation of the device abovedescribed the water circulates by thermo-siphonic action from the standtank 10 through the heating chamber 18, the hot water accumulating inthe upper part of tank 10. If no water is used by the household for aconsiderable length of time, or if the amount used isinconsiderable, theamount of hot water in tank 10 increases and the lower edge of the hotwater works downward until it reaches the thermostat 33 which thereuponoperates to reduce the amount of gas passing to burner 32. If one ormore faucets in the house are opened, the hot water coming from chamber18, passes directly to the house piping instead of into tank 10. Owingto the small amount of water in chambers 18, the water passing therefromto the house piping is at a high temperature for domestic uses. A draftof hot water through the house faucets in excess of the amount that canbe supplied directly from chamber 18, is supplied from hot water storedin tank 10, within reasonable limits. The burner is designed to consumeonly slightly more gas per hour than that estimated to be required. forthe average consumption of hot water of the household. The demand on thegas main and on the gas making equipment therefore never rises above avery limited amount and it is therefore profitable for the gas companyto supply gas to water heaters within the present invention at arelatively low flat rate or rate per month.

While I have described above and illustrated in the accompanying drawingspecific forms of apparatus according to the present invention, it willbe understood that I do not limit myself to details of the disclosure,it being the intention to claim herein all novelty occurring in thepresent disclosure as broadly as the state of the art will permit. Ithas been found, moreover, that the water heating arrangement disclosedherein is very effective in preventing trouble from scale in districtswhere the public water supply is hard water.

Having thus described my invention, I claim:

1. In a water heater, a water heating chamber substantially O-shaped invertical elevation comprising two spaced upright legs joined to eachother at top and bottom by water connection cap closures, a fire tube ofinverted ii-shape mounted within said chamber, each leg of said firetube being mounted coaxially within one leg of said chamber with itsopen end sealed in an aperture in the bottom cap closure, and a burnerarranged to discharge upwardly into one leg of said fire tube.

2. The combination as set out in claim 1 in which the legs of the firetube are of substantially one inch smaller diameter than the legs of thewater chamber.

3. In a water heater, a water heating chamber substantially Q-shaped invertical elevation comprising two spaced upright parallel legs joinedtoeach other top and bottom by water connection cap closures, and a fire,tube of inverted U-shape supported within said chamber by said bottomcap closure with the lower open end of each of its legs extendingthrough and sealed in an aperture in said bottom cap closure in positionsuch that each fire tube leg extends coaxially within one leg 7 of saidchamber throughout the full length of said chamber leg, the U-bend ofsaid fire tube being located coaxially within the top cap closure ofsaid chamber. 7

In testimony whereof I aflix my signature.

. J AS. L. STONE.

